Do you know why your morning coffee from a paper cup sometimes smells like cardboard? It's not the paper itself! The main culprit is the inner layer, usually made of polyethylene, which prevents leaks. This thin barrier is the culprit. At temperatures above 70 degrees Celsius, polyethylene begins to emit volatile organic compounds, which are absorbed by the hot drink. These aren't cardboard, but chemical vapors. Studies have shown that after just 10 minutes, the flavor becomes noticeable. Incidentally, the paper used for the cups, often made from virgin pulp, contains glue and bleaching agents. Hot liquid intensifies their odor, which mingles with the aroma of the coffee. For example, such cups are produced by Huhtamaki and Dart Container. Interestingly, the severity of this odor also depends on the quality of the coffee itself. High-quality varieties, especially light roasts, are more sensitive to off-flavors. Cheaper blends and dark roasts mask the problem better. To enjoy a purer taste, use ceramic or reusable stainless steel cups. This will not only enhance your drink but also help the planet. After all, less than 1% of the millions of disposable cups used are recycled.